A Colombian urban strategist has argued Perth can create a better, cheaper public transport system using buses instead of light rail, but not everyone agrees.

Enrique Penalosa is the former mayor of Bogota and a keynote speaker at a Perth symposium on creating better cities this week.

He told 720 ABC Perth that buses could be more efficient and move just as many people as rail.

"Here people think rail is the big solution to mobility but actually if you have buses on exclusive lanes with prepaid stations, you can move far more people than most subways in the world," Mr Penalosa said.

In Colombia, Mr Penalosa's administration looked to buses as rail was too expensive to build and operate, and would have required ongoing subsidies.

Buses ... are about as attractive to development as a truck way.

Jemma Green, Curtin University

"Buses can go nearer to where people live and if they have exclusive lanes they can have the same speed and higher capacity than trains," he said.

"What gives capacity to a system are not wheels that are metal but exclusive right of way without any obstacles like traffic lights. Then buses can do many wonderful things."

It's a message that is likely to find favour with Transport Minister Dean Nalder, who earlier this year announced the government was axing the promised $2.5 billion Max Light Rail project for Perth's northern suburbs, and replacing it with a rapid bus transit system.

"What we're talking about is the same project over the same route, providing the customer with exactly the same experience," Mr Nalder said in March.

'Light rail better in the long term'

Jemma Green from Curtin University's Sustainable Policy Institute said buses may be cheaper in the short term, but they were not popular with the public and did not promote urban development.

"Bogota has vastly improved their problem of congestion by using the bus system," she told 720 ABC Perth.

"That's the right thing for them but it's not necessarily for here in Australia."

Ms Green said overall public transport use was going up but bus patronage was in decline.

"Buses are not fast enough, they are not attractive enough. You can't read on a bus, you can read on light rail. The ride experience is completely different," she said.

Ms Green said buses were cheaper in the short term, but did not inspire the kind of land development that cities like Perth needed to expand.

"If land development is packaged into rail development then it doesn't actually cost more," she said.

"Buses don't facilitate land development at all, they are about as attractive to development as a truck way.

"Bus services are more flexible, but that is part of the problem.

"People know bus routes can change, and they are not attractive to build around."

Ms Green said exclusive bus lanes had been tried without success in Sydney and were now being removed.

"Light rail is going up all over Australia and it is actually working," she said.

The Perth Max Light Rail project was scrapped in favour of a bus service in the wake of Western Australia's downgraded credit rating, but Jemma Green argued the state government could look to the private sector to provide a solution.

"I think the government needs to put out a call for expressions of interest to the private sector to build and operate the light rail, and package up the land as part of it," she said.

"It has been done in other parts of the world. We need to look at innovative ways to finance things and we can't just back away from stuff because it looks too complicated."